Technical Field
This disclosure relates to an image forming apparatus.
Description of the Related Art
Image forming apparatuses are well known which include an image forming device having plural image bearers and which perform a compulsory toner consumption processing such that a toner image (hereinafter referred to as a compulsory consumption toner image) is forcibly formed on at least one of the plural image bearers to consume the toner, thereby making it possible to discharge deteriorated toner from the image forming device.
For example, there is a proposal for an image forming apparatus which includes, as the plural image bearers, four photoconductors on which yellow (Y), magenta (M), cyan (C) and black (K) toner images are formed respectively. In the image forming apparatus, a narrow Y toner image extending in the main scanning direction (i.e., optical scanning direction when an electrostatic latent image is formed on the photoconductor) is forcibly formed on the Y photoconductor while a narrow C toner image extending in the main scanning direction is forcibly formed on the C photoconductor, and the Y and C toner images are transferred to a transfer belt serving as a transfer medium so as to be overlaid (i.e., to form a combined Y and C toner image). In addition, a narrow M toner image extending in the main scanning direction is forcibly formed on the M photoconductor while a K toner image extending in the main scanning direction is forcibly formed on the K photoconductor, and the M and K toner images are transferred to the transfer belt so as to be overlaid (i.e., to form a combined M and K toner image). In this regard, the Y and C combined toner image and the M and K combined toner image are arranged side by side in the sub-scanning direction (i.e., moving direction of the transfer belt) with a predetermined space therebetween.
It is described in the proposal that since two combined color toner images are formed side by side, the travel distance of the transfer belt in the compulsory toner consumption processing can be reduced so as to be shorter than in a case in which Y, M, C and K toner images are formed side by side without being overlaid.